Pneumatic cushion for vehicles.



G. S. GURNEY.

PNEUMATIC CUSHION FOR VEHICLES.

APYLIOATION FILED NOV. 21, 1910.

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Patented Oct. 10, 1911.

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i tWQQ mahboz CE 'aawfiy aria cm CALEB STEVENS GURNEY, OF PORTSMOUTH,NEW HAMPSHIRE.

PNEUMATIC CUSHION FOR VEHICLES.

Specification of Letters Patent. Patented Oct, 10, 1911 Applicationfiled November 21, 1910. Serial No. 593,565.

To all whom it may concern:

Be it known that I, CALEB STEVENS GUR- NE a citizen of the UnitedStates, residing at ortsmouth, in the county of Rockingham and State ofNew Hampshire, have invented certain new and useful Improvements inPneumatic Cushions for Vehicles; and I do declare the following to be afull, clear, and exact description of the invention, such as will enableothers skilled in the art to which it appertains to make and use thesame.

This invention relates to improvements in pneumatic cushions forvehicles.

One object of the invention is to provide a cushion of this characterhaving an improved construction and arrangement of air inlet anddischarge passages and means for opening and closing the same at theproper time for admission and discharge of air from the cylinder wherebythe air forms a perfect cushion on both sides of the piston, thusyieldingly supporting the weight of the vehicle and preventing the quickrebounding of the same. Another object is to provide a cushion of thischaracter which will be simple, strong and durable in construction,eflicient and reliable in operation, and well adapted to the purpose forwhich it is designed.

With these and other objects in view, the invention consists of certainnovel features of construction, combination and arrangement of parts aswill be more fully described and particularly pointed out in theappended claim.

In the accompanying drawings, Figure 1 is a vertical longitudinalsection of my improved pneumatic cushion; Fig. 2 is a horizontalsectional view of the same on the line 22 of Fig. 1; Fig. 3 is a detailview of the piston and valves controlling the inlet and discharge of theair to and from the cylinder.

In the embodiment of the invention, I provide a cylinder 1 which may beof any suitable size and is closed at its lower end and provided on itsupper end with a head 2 which is bolted or otherwise suitably securedthereto. On the lower end of the cylinder is formed a socket 3 in whichis adapt-. ed to be secured the ball end 4 of a cylinder attaching bolt5, by means of which the cylinder may be secured in any suitableposition to the axle of the vehicle, preferably between the upper andlower branches of the elliptical spring. In one side of the cylinder, inthe upper portion thereof, a slight distance above the center, is formeda vertical series of air inlet and discharge passages 6, while in thelower portion of the cylinder, below the center, is arranged a verticalseries of air inlet and discharge passages 7.

Slidably mounted in the cylinder 1 is an air compressing piston 8, saidpiston preferably comprising upper and lower metal clamping disks 9,between which is arranged a disk 10 formed of suitable packing materialwhereby the edges of the piston will form a close engagement with thesides of the cylinder. The disks 9 and 10 are clamped together and inoperative engage- ,ment with the inner end of a piston rod 11 byclamping nuts 12, which are screwed onto the threaded inner end of thepiston rod, as shown. The outer end of the piston rod is adapted to besecured in any suitable manner or by any suitable means (not shown) tothe lower side of the vehicle body or frame.

To the upper side of the piston 8 and closely engaging the inner side ofthe cylinder having the air inlet and discharge passages, is an uppersegmental valve plate 13, while to the under side of the pistonimmediately below the valve 13 is arranged a similarvalve plate 14. Thevalve plates 13 and 14: have a curvature corresponding to the curvatureof the inner surface of the cylinder, which they closely engage. Theplates 13 and 14 have arranged on their inner ends attaching frames 15in which are formed screw holes adapted to receive fastening screws 16,which are driven into the disks 9" forming the opposite sides of thepiston.

In the operation of the cushion, as the piston is forced down by'theweight of the vehicle thereon, the lower valve 14: will be moved overthe air assages 7 in the'lower portion of the cylin er, thus graduallycut tingofi the escape of the air which is being forced out by thedownward movement of the piston. When the piston has moved downwardly asuflicient extent to cause the valve 14 to close the lowermost passage 7further escape of the air is prevented and the remaining air in thelower end of the cylinder is compressed and forms a cushion whichyieldingly supports the weight of the vehicle. By thus graduallycutting. off the discharge of the air in the lower end of the cylinder,the downward movement of the piston is gradually brought to a pointwhere the air is compressed to a sufficient extent to form a cushion forsupporting the Weight of the vehicle, thus preventing any abruptstoppage of the piston which would cause a shock or jar to the vehicle.As the piston is thus forced downwardly the upper valve '18 willgradually uncover the upper series of air passages 6, thereby graduallydrawing air into the upper end of the cylinder,

' which will form a cushion in said end and such that all the upperopenings and all the lower openings cannot be covered nor uncovered atthe same time, so that as the air is gradually forced out through oneseries of openings it is simultaneously and at the same rate drawn inthrough the other series of openings. Inasmuch as the air is not forcedout nor drawn in through a single large opening there is no suddenincrease of pressure on either side of the piston, jaut the compressionof air against the end of the cylinder is very gradual so that thecushioning action is not abrupt and gradually arrests the movement ofthe vehicle instead of accomplishing that result suddenly and sharply soas to increase the jolting efi'ect. Furthermore, the piston cannotassume a position in which both series of openings will be above orbelow the piston and, consequently, there is no such preponderance ofpressure upon either side of the piston at any time as will interferewith the free movement of the same under the vibrations of the vehicle.

From the foregoing description, taken in connection with theaccompanying drawings, the construction and operation of the inventionwill be readily understood without requiring a more extendedexplanation.

Various changes in the form, proportion and the minor details ofconstruction may be resorted to without departing from the principle orsacrificing any of the advantages of the invention, as defined in theappended claim.

Having thus particularly described my invention, what I claim is:

A device for the purpose set forth comprising a cylinder closed at bothits ends and provided in one side with upper and lower vertical seriesof lateral openings extending only partway to the ends of the cylinder,a piston slidably mounted in said cylinder, and valve plates secured tothe upper and lower sides of the piston and fitting closely -against theinner surface of the cylinder to alternately cover and uncover thelateral openings in the cylinder when the piston is reciprocated.

In testimony whereof I have hereunto set my hand in presence of twosubscribing witnesses.

CALEB STEVENS GURNEY.

WVitnesses HELEN M. QUINN, GUY E. COREY.

